BRITISH WARBLERS 



tion or thick foliage, and therefore might readily escape 

 detection. In fact it is necessary to rely to some extent 

 on the behaviour of the male in order to assure oneself of her 

 presence, so that to observe her plucking the first piece of 

 decayed vegetation with which to form the foundation of her 

 nest is no easy matter. The male takes but a small part in 

 the actual construction of the nest, his behaviour being in 

 this respect similar to that of the male Eeed Warbler, 

 who labours but little to obtain the necessary material and 

 weave it into the nest. But although he seems unwilling to 

 share this work with his mate, yet he takes great pains to 

 follow her closely, whenever she is engaged in searching for 

 material or in deciding the actual position the nest is to 

 occupy. In thus accompanying her closely when at work 

 he resembles not only the male Eeed Warbler but the males 

 of other species also ; and this habit of keeping a close 

 attendance upon the female, of following her from tree to 

 tree and bush to bush, desirous apparently of being a spectator 

 of all her work and acquainted with all her movements, must 

 be sexual in origin. After the nest has been built and laying- 

 has commenced the peculiarity is not so striking ; true it is 

 that he can often be seen beside her, but the craving for her 

 companionship does not seem to be then so pronounced. His 

 actual conduct during these few days gives us some insight 

 into the true meaning of this close companionship, for we can 

 frequently witness those playful contests which we know to 

 be characteristic of sexual activity. The responsibility for 

 these contests does not always rest with the male, but there 

 is no doubt that we can more often mark their beginnings in 

 him, although at times they seem to be almost mutual. One 

 sees on such occasion a spreading and raising of wings on 

 the part of one of the sexes, followed by a flying together and 

 a touching of bills, accompanied by an uttering of the call note 

 or a few phrases of the song. Of the two the male is more 

 frequently the one that quivers his wings, and on his approach 

 the female is sometimes accustomed to spread her tail and 



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